Most parents do not have the luxury to be physically present and close to their children when they spend time surfing the Web. Even those stay at home mothers usually cannot dedicate all their spare time to making sure that their children are being supervised at all times. It might be a good idea for parents to seek other solutions that would allow them to be aware to know what it is that their kids do when in front of their computers.
Kids will always be kids and they will always want to have access to something that you do not want them to look at. You will need to use common sense while choosing what they should do and what they shouldn’t.